Autostereoscopic 3D enables a user to observe three dimensional images without wearing special 3D glasses. With the increasing popularity of 3D imaging, autostereoscopic 3D displays are gaining popularity in several product areas, such as hand held mobile devices, tablets, laptops, monitors, TVs, as well as signage and industrial displays. Also, movie theaters, as well as in such high resolution applications as are necessary in medical devices including CAT scans, ultrasonic equipment, x-ray surgery, and in military and public information displays utilize such displays. Anything from big magazines to billboards are becoming increasingly popular. One major type of autostereoscopic 3D technology is to use a lenticular array (sometimes “lenticular) to project images to the eyes and create a 3D illusion. The lenticular array or grating is formed by a plurality of a cylindrical lenses that create views of the image that are different for each eye of the viewer when the lenticular array is placed in front of a pixelated image source. The lenticular array needs to be manufactured with micron-scale accuracy in order to properly locate the cylindrical lenses relative to the pixels of the image source.
Conventionally, such lenticular arrays are made of plastics, which can be fabricated on an industrial scale by injection molding, extrusion, press embossing, or UV embossing at very low cost. Plastic lenticular arrays, however, suffer from several intrinsic issues such as dimensional instability from thermal expansion and mechanical stretching, clinical and UV instability of materials, poor scratch resistance, difficulty in cleaning, dim images due to light scattering and light reflection from curved and lenticular surfaces.
An alternative to plastic lenticulars is an all glass lenticular array which offers several advantages such as low thermal expansion, high mechanical stability, chemical resistance, scratch resistance, but such glass lenticulars are expensive, and a practical way to reduce costs with high quality glass lenticulars is still hard to achieve. Furthermore, because it is difficult to apply anti-glare and anti-reflection coatings on a curved lenticular surface, glass lenticulars will also suffer from image degradation issues due to light scattering reflections.
Further, besides plastic and glass lenticulars, there are hybrid type lenticular systems where plastic lenticular arrays have been bonded onto an underlying flat piece of glass substrate to provide better dimensional stability. This approach still has issues with warping, and as the external surface is still plastic, its chemical and mechanical durability is poor, and the light reflection/scattering issue is still unsolved.